Yamaha - Water Pump Repair Kit Cooling System 6E0-W0078-A3-00. Overview. When you're going into a Yamaha water pump, it usually makes sense to do it right the first time. I've seen too many quick impeller swaps turn into repeat jobs because the rest of the components were already worn. A full repair kit like this takes care of everything in one shot and saves you from coming back in later. Once it's rebuilt properly, you get solid water flow and dependable cooling every time you run it.. Key Features. Complete Pump Service Kit - Includes essential components needed for a full water pump rebuild.. Restores Cooling Performance - Helps bring water pressure and flow back to proper levels.. Matched Internal Components - Designed to work together for consistent fit and operation.. Durable Marine Materials - Built to handle heat, friction, and debris in real-world conditions.. Engine & Boat Compatibility. Designed for Yamaha 2-stroke outboard engines using standard water pump systems. Commonl